Neuroticism may also influence an individual’s health behaviour patterns and,
thereby, their health outcomes. Neuroticism is associated with more smoking and
alcohol abuse and less healthy eating and exercise (Booth-Kewley and Vickers, 1994).
For example, in relation to smoking, longitudinal studies have found that those with
higher neuroticism scores are more likely to take up smoking and maintain the habit
(e.g. Canals, Bladé and Domènech, 1997). Thus negative health outcomes associated
with higher levels of neuroticism might be due, in part, to those with higher levels of
neuroticism being more likely to smoke. Thus smoking may mediate the neuroticism–
health relationship. Shipley et al. (2007) recently reported the impact of neuroticism
on mortality in a sample of over 5,000 UK adults over a period of 21 years. High neu -
roticism was associated with mortality from all causes and with mortality from
cardiovascular diseases. However, these effects became non-significant after controlling
for age, gender, social class, education, smoking, alcohol consumption and physical
activity. This would suggest that the effects of neuroticism on mortality may be ex -
plained by socio-demographic factors and health behaviours. A final mechanism by
which neuroticism may impact on health is through physiological changes. Research
has highlighted the impact of high levels of neuroticism on reduced immune function
(Kiecolt-Glaser et al., 2002) suggesting another potential mechanism through which
neuroticism impacts on various health outcomes.
EXTRAVERSION
Extraversion is a further Big Five personality trait where those with high levels of the
trait are referred to as extraverts and those with low levels referred to as introverts.
Extraverts tend to be outgoing, social, assertive and show high levels of energy; they
also tend to seek stimulation and so enjoy new challenges but get easily bored. In
contrast introverts tend to be more cautious, serious and avoid over-stimulating
environments and activities (Eysenck, 1967; Costa and McCrae, 1992). There are a
number of well-established measures of extraversion–introversion. For example,
Eysenck and Eysenck’s (1964) measure contains items such as ‘Are you usually
carefree?’ and ‘Do you enjoy wild parties?’ with extroverts more likely to agree with
these types of items (see Figure 6.2). Extraversion has been found to be associated with
positive psychological well-being and better physical health. For example, extraverts
report more positive moods and higher levels of pleasure and excitement. Costa and
McCrae (1980) showed that extraversion measured at one time point significantly
predicted happiness 10 years later. Extraverts tend to report lower rates of coronary
heart disease, ulcers, asthma and arthritis (Friedman and Booth-Kewley, 1987). Some
research has reported effects for extraversion on mortality. For example, Shipley et al.
(2007), in addition to examining the impact of neuroticism on mortality, also examined
the impact of extraversion. In their sample of over 5,000 UK adults examined over a
21-year period, extraversion was found to be significantly associated with a reduced
risk of respiratory disease.
The explanation for the relationship between extraversion and health is not entirely
clear. It is possible that this relationship is attributable to extraverts experiencing lower
levels of stress, better coping strategies or more social support compared to introverts
but there is as yet no strong evidence to support these explanations. Similarly, in
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